The present invention relates to testing of data packet signal transceivers, and in particular, to systems and methods for parallel testing of multiple such devices.
Many of today's electronic devices use wireless technologies for both connectivity and communications purposes. Because wireless devices transmit and receive electromagnetic energy, and because two or more wireless devices have the potential of interfering with the operations of one another by virtue of their signal frequencies and power spectral densities, these devices and their wireless technologies must adhere to various wireless technology standard specifications.
When designing such devices, engineers take extraordinary care to ensure that such devices will meet or exceed each of their included wireless technology prescribed standard-based specifications. Furthermore, when these devices are later being manufactured in quantity, they are tested to ensure that manufacturing defects will not cause improper operation, including their adherence to the included wireless technology standard-based specifications.
For testing these devices following their manufacture and assembly, current wireless device test systems employ a subsystem for analyzing signals received from each device. Such subsystems typically include at least a vector signal analyzer (VSA) for analyzing signals produced by the device, and a vector signal generator (VSG) for generating signals to be received by the device. The analyses performed by the VSA and the signals generated by the VSG are generally programmable so as to allow each to be used for testing a variety of devices for adherence to a variety of wireless technology standards with differing frequency ranges, bandwidths and signal modulation characteristics.
Among the wireless technologies being tested are those where the transmitters and receivers of the devices operate on the same frequency. One such operation is time-division-duplex (TDD), with one increasingly common example known as Bluetooth. When performing simultaneous testing of two or more such devices employing TDD technologies, there is a possibility of error caused during testing due to variations in the start times of the devices. For example, in one scenario, one or more devices may synchronize to a response data packet generated by another device under test (DUT) rather than responding to the intended test data packet generated by the tester (e.g., by the VSG). As a result, a DUT that becomes synchronized to the wrong signal will remain so and, therefore, produce erroneous or invalid test results.
Accordingly, a method for synchronizing multiple TDD DUTs that avoids such improper synchronization scenarios would advantageously reduce faulty device synchronization and test time, and thereby reduce overall testing costs on a per device basis.